This invention relates generally to packaging integrated circuits.
Integrated circuits, such as microprocessors, may be packaged in various configurations. One such configuration is called a land grid array package. With land grid array packaging, integrated circuit die may be coupled to circuit boards through sockets that electrically and mechanically couple the integrated circuit die to the circuit board. In some cases, the connection may be via socket spring fingers which contact lands on the integrated circuit packages to make a land grid array connection system.
Often, a number of components may be connected together to form a stack. In one example a voltage regulator module board may be assembled on a motherboard through a land grid array connector. The voltage regulator module and motherboard are clamped together between a bolster plate under the motherboard. A heat sink may be positioned on top of the voltage regulator module board. Pairs of standoffs on the bolster plate are used to control the space in between the bolster plate and the heat sink.
Due to the dimensional tolerances of the mechanical parts, the distance between the bolster plate and the heat sink varies on individual assembly. Part of this stack tolerance can be absorbed by the flexibility of the land grid array springs. However, the bending range of land grid array springs is limited and cannot absorb the entire stack tolerance.
In the meantime, a certain level of pressure is required to press the land grid array onto the land pads on the motherboard to meet the requirement of good electrical design.
Thus, there is a need for better ways to connect integrated circuits to boards in the form of stacks.